红外增温对库尔勒香梨越冬期树干形成层主要生理参数的影响
The effect of infrared heating on physiological parameters of korla fragrant pear trunk cambium during over-wintering period

为了探讨越冬期树干形成层温度变化对形成层组织生理参数的影响，以库尔勒香梨为实验材料，在太阳辐射和气温达到日最大值的时间段，利用控温红外灯将实验组树干阳面形成层温度分别增温达到16℃、19℃、22℃、25℃、28℃、31℃、34℃，采用热电偶温度传感器同时连续监测形成层温度并结合主要生理参数的变化，分析越冬期间树干形成层温度变化引起的融冻交替对树干组织主要生理参数的影响。结果表明，增温达到最大阳面形成层温度日较差的处理条件下，SOD、POD和CAT活性比对照分别降低了83.60%、84.62%、47.56%，相对电导率和可溶性蛋白含量分别升高了41.46%、46.81%；生理指标和形成层温度均呈负相关，其中CAT、可溶性蛋白和相对电导率呈显著性负相关。形成层温度日较差或融冻交替幅度与各生理参数均呈负相关，其中CAT、可溶性蛋白和相对电导率呈显著性负相关。保护酶系中，SOD对形成层温度变化最为敏感；虽然POD保护作用稍微迟钝，但在较强烈的形成层温度变化的条件下起到最好的保护作用；在形成层温度强烈波动的情况下，CAT保持最小变化幅度；可溶性蛋白通过调节渗透势，减轻细胞伤害程度。
To explain the effect of cambium temperature changes on its physiological parameters during over-wintering period, infrared lamps was used to heat the sunny side cambium of Korla fragrant pear trunk to temperature treatment of 16℃, 19℃, 22℃, 25℃, 28℃, 31℃ and 34℃,respectively, during diurnal maximum solar radiation and air temperature. The actual temperature of trunk cambium was measured by thermocouple temperature sensors and its physiological factors were measured simultaneously. Results showed that, after increasing the diurnal cambium temperature difference to the maximum value, compared with the control, the activities of SOD, POD and CAT were declined by 83.60%, 84.62% and 47.56%, and the relative electrical conductivity and soluble protein content were increased by 41.46%,46.81%. The physiological indexes were negatively co rrelated with the cambium temperature and the correlation of CAT, soluble protein content and relative conductivity was significant. The diurnal cambium temperature difference or freezing-heating cycle was negatively correlated with the physiological parameters and the correlation of CAT, soluble protein content and relative conductivity significantly. Moreover, SOD activity showed the most sensitive response to the cambium temperature change. POD has played a protection against the temperature change while its activity change was smaller than SOD. CAT activity changed the smallest. The soluble protein could relieve the degree of cell damage by adjusting the osmotic potential.